Uncover the mystery of HTML5 mobile page creation

Beginning with the mobile side, you need to be prepared with some basic knowledge:

Figuring out the rem,em,px relationship in CSS

PX Features

1. IE cannot adjust the font size using PX as the unit;

2. Most of the foreign sites can be adjusted because they use EM or REM as font units;

3. Firefox can adjust PX and em,rem, but more than 96% of Chinese netizens use IE browser (or kernel).

px Pixels (Pixel). Relative length units. Pixel px is relative to the display screen resolution. (quoted from CSS2.0 manual)

EM is the relative length unit. The font size relative to the text within the current object. If the font size of the current inline text is not artificially set, the default font size is relative to the browser. (quoted from CSS2.0 manual)

The default font height for any browser is 16px. All non-adjustable browsers are compliant with: 1EM=16PX. So 12px=0.75em,10px=0.625em. To simplify the conversion of font-size, you need to declare font-size=62.5% in the body selector in the CSS, which makes the EM value 16px*62.5%=10px, so 12px=1.2em, 10px=1em, That means you just have to divide your original PX value by 10 and then put EM in as the unit.

EM features

1. The value of EM is not fixed;

2. Em inherits the font size of the parent element.

So when we are writing CSS, we need to pay attention to two points:

1. Declare font-size=62.5% in the body selector;

2. Divide your original PX value by 10 and then replace it with EM as the unit;

3. Recalculate the EM values of the enlarged fonts. Avoid duplicate declarations of font size.

REM Features

REM is a new relative unit of CSS3 (root em, root em), and this unit has aroused widespread concern. What is the difference between this unit and EM? The difference is that when you use REM to set the font size for an element, it is still relative size, but relative to the HTML root element. This unit is a combination of relative size and absolute size of the advantages in one, through it can only modify the root elements in proportion to adjust all font size, but also to avoid the size of the font-layer composite chain reaction. Currently, in addition to IE8 and earlier versions, all browsers support REM. For browsers that do not support it, the workaround is simple enough to write an absolute unit statement. These browsers ignore font sizes that are set with REM.

With these basics in hand, we can do it,

After getting the design draft, if it is 640px, we will follow the size of 640px, and then all units are calculated according to REM, the HTML needs to set the font size {font-size:1px;}, and then all the tags can be followed by REM conversion, How to convert here needs to know first.

Then add a section of JS to the page:

(function (Doc, win) {varDocel =doc.documentelement, Resizeevt='Orientationchange' inchWindow?'Orientationchange':'Resize', Recalc=function () {varClientWidth =Docel.clientwidth; if(!clientwidth)return; DocEl.style.fontSize=1* (clientwidth/640) +'px';        }; //Abort If browser does not support AddEventListener        if(!doc.addeventlistener)return; Win.addeventlistener (Resizeevt, Recalc,false); Doc.addeventlistener ('domcontentloaded', Recalc,false); }) (document, window);

Reset the font size of the HTML so that the page can be self-adapting. If not through the JS there is another way is through the media query, this is also very convenient

<link rel= "stylesheet" href= "stylea.css" media= "screen" ><link rel= "stylesheet" href= "Styleb.css" media= " Screen and (max-width:800px) "><link rel=" stylesheet "href=" stylec.css "media=" screen and (max-width:600px) ">

Uncover the mystery of HTML5 mobile page creation